PMID- 29544317
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180612
LR  - 20180612
IS  - 1089-7690 (Electronic)
IS  - 0021-9606 (Linking)
VI  - 148
IP  - 10
DP  - 2018 Mar 14
TI  - Quantum theory of multiscale coarse-graining.
PG  - 102335
LID - 10.1063/1.5010270 [doi]
AB  - Coarse-grained (CG) models serve as a powerful tool to simulate molecular systems 
      at much longer temporal and spatial scales. Previously, CG models and methods 
      have been built upon classical statistical mechanics. The present paper develops 
      a theory and numerical methodology for coarse-graining in quantum statistical 
      mechanics, by generalizing the multiscale coarse-graining (MS-CG) method to 
      quantum Boltzmann statistics. A rigorous derivation of the sufficient 
      thermodynamic consistency condition is first presented via imaginary time Feynman 
      path integrals. It identifies the optimal choice of CG action functional and 
      effective quantum CG (qCG) force field to generate a quantum MS-CG (qMS-CG) 
      description of the equilibrium system that is consistent with the quantum 
      fine-grained model projected onto the CG variables. A variational principle then 
      provides a class of algorithms for optimally approximating the qMS-CG force 
      fields. Specifically, a variational method based on force matching, which was 
      also adopted in the classical MS-CG theory, is generalized to quantum Boltzmann 
      statistics. The qMS-CG numerical algorithms and practical issues in implementing 
      this variational minimization procedure are also discussed. Then, two numerical 
      examples are presented to demonstrate the method. Finally, as an alternative 
      strategy, a quasi-classical approximation for the thermal density matrix 
      expressed in the CG variables is derived. This approach provides an interesting 
      physical picture for coarse-graining in quantum Boltzmann statistical mechanics 
      in which the consistency with the quantum particle delocalization is obviously 
      manifest, and it opens up an avenue for using path integral centroid-based 
      effective classical force fields in a coarse-graining methodology.
FAU - Han, Yining
AU  - Han Y
AUID- ORCID: 0000000265772015
AD  - Department of Chemistry, James Frank Institute, and Institute for Biophysical 
      Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
FAU - Jin, Jaehyeok
AU  - Jin J
AD  - Department of Chemistry, James Frank Institute, and Institute for Biophysical 
      Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
FAU - Wagner, Jacob W
AU  - Wagner JW
AUID- ORCID: 0000000171941279
AD  - Department of Chemistry, James Frank Institute, and Institute for Biophysical 
      Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
FAU - Voth, Gregory A
AU  - Voth GA
AUID- ORCID: 0000000232676748
AD  - Department of Chemistry, James Frank Institute, and Institute for Biophysical 
      Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Chem Phys
JT  - The Journal of chemical physics
JID - 0375360
EDAT- 2018/03/17 06:00
MHDA- 2018/03/17 06:01
CRDT- 2018/03/17 06:00
PHST- 2018/03/17 06:00 [entrez]
PHST- 2018/03/17 06:00 [pubmed]
PHST- 2018/03/17 06:01 [medline]
AID - 10.1063/1.5010270 [doi]
PST - ppublish
SO  - J Chem Phys. 2018 Mar 14;148(10):102335. doi: 10.1063/1.5010270.